What can an unlicensed assistant legally do?

An unlicensed assistant can legally host an open house because this activity does not require a real estate license. Hosting an open house involves facilitating the viewing of a property, which is typically viewed as a supportive task that does not include negotiating terms, providing legal advice, or creating binding agreements.

Engaging in tasks such as negotiating contracts, providing legal advice, or writing listing agreements requires the expertise and licensure that comes with being a qualified real estate agent or broker. These activities involve legal responsibilities and implications that cannot be fulfilled by someone who is not licensed in real estate. Therefore, hosting an open house is a suitable and permissible activity for an unlicensed assistant, making this the correct answer.